dobbins



. March 17, 1964 Filed Dec. 19, 1960 w. J. DOBBINS CAN SEALING MACHINE 4 Sheets-Sheet 1 INVENTOR. WALTZR J/IMfS DHEAV/VS w. J. DOBBlNS 3, ,917

Filed Dec. 19, 1960 "Hum INVENTOR. W/IL 75/? I l/141530066016 BY 22/ 1 Z7 M fi r March 17, 1964 Filed Dec. 19. 1960 W. J. DOBBINS CAN SEALING MACHINE 4 Sheets-Sheet 3 BY ig/Mal YM March 17, 1964 w. J. DOBBINS 3,124,917

CAN SEALING MACHINE Filed Dec. 19, 1960 4 SheetsSheet 4 52 fl J (9% 71 5 United States Patent Ofifice 3,124,917 Patented Mar. 17, 1964 3,124,917 CAN SEALING MACHINE Walter James Dobbins, Lalre Zurich, llll., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Dec. 19, 1966, Ser. No. 76,916 6 Claims. (Cl. 53-88) The present invention relates to a machine for sealing containers or cans having vent holes provided therein and has particular reference to sealing the vent hole with a resilient material plug.

In the filling of containers of the type in which the product is held under and is dispensed by a fluid pressure exerted against an internal piston, such as the aerosol type containers, it is extremely difficult to introduce the fluid pressure medium when such medium is confined in the bottom of the containers. Several methods have been tried, including the attachment of the bottom end to the container after the container has been filled and while the pressure space is held under pressure, but most of these involve handling the containers in an inverted position with resultant difficulties in feeding the containers into and through the machine.

The instant invention contemplates pressurizing the containers in an upright position and through a vent hole in the bottom of the container. In such a container, the product is introduced and the internal piston placed in position and then the bottom closure is attached in the usual manner of interfolding flange portions of the closure and the body to produce the well known double seam. A vent hole is provided in the bottom closure. The pres sure space in the container is then vacuumized and pressurized by introduction of a fluid pressure medium and the vent hole is then sealed with a resilient material plug, preferably a rubber plug. These vacuumizing, pressurizing and sealing operations are effected while the container is in an upright position so that the container may be readily conveyed into and out of the machine while resting on its bottom end seam.

It is therefore an object of the instant invention to provide a machine for vacuumizing, pressurizing and sealing a container having a vent hole in its bottom closure so that the containers may be readily fed into and out of the machine in an upright position.

It is also an object of the invention to provide such a machine in which the vacuumizing, pressurizing and sealing is effected through a single channel which is aligned with the vent hole in the container to be sealed so as to effect simplicity in machine construction and efiicient operation.

It is also an object of the invention to provide in such a machine a novel means of cutting off a plug from a string of resilient material and by the same means transfer the cut off plug into a position in alignment with the container vent hole for sealing insertion thereinto.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

FIGURE 1 is a side elevation of a container of the type to be sealed by the machine of the instant invention;

FIG. 2 is an enlarged fragmentary sectional view of the bottom of the container showing the vent hole in sealed condition;

FIG. 3 is a top plan view of a machine embodying the 'instant invention and utilized for sealing the container shown in FIG. 1;

FIG. 4 is a side elevation of the machine as viewed from the right in FIG. 3, with parts broken away;

FIG. 5 is a sectional view taken substantially along the line 55 in FIG. 3, with parts broken away;

FIGS. 6 and 7 are enlarged sectional views taken substantially along the respective lines 66, 7-7 in FIG. 3; and

FIG. 8 is an enlarged sectional view taken substantially along the line 38 in FIG. 7.

As a preferred and exemplary embodiment of the instant invention the drawings disclose a machine for vacuumizing and pressurizing the product propellant space of a sheet metal aerosol type container A (FIGS. 1 and 6) having a concave sheet metal bottom closure B (see also FIG. 2) attached to the body of the container by a double seam C and containing a vent hole D through which the vacuumizing and pressurizing is effected and which after these operations, is sealed with a resilient plug E preferably made of rubber. The propellant space within the container is defined by a hollow piston F disposed in the bottom of the container as shown in FIG. 6. A dispensing nozzle G (FIG. 1) is provided on the top end of the container.

In the machine, one end of a cylindrical string H (FIG. 7) of rubber is fed into a reciprocable cut-off-transfer member or slide 21 which cuts off a plug E from the string H and simultaneously advances the plug to a sealing station I. At the sealing station I a container A is received in an upright position on a yieldable support or pad 22 (FIG. 6) which is disposed above the cut-off-transfer slide 21 and which locates the container with its vent hole D in axial alignment with the plug in the slide. As soon as the container is received on the pad 22 it is clamped in position against the pad by a vertically reciprocable clamp member 23 (FIGS. 4 and 5) which engages against and encloses the top end of the container.

While the container A is thus held clamped against the pad 22, its propellant space in the bottom of the container is first vacuumized, then filled with a fluid pressure medium, and finally the plug E is pushed up into the vent hole D to seal the container and thereby hold the pressure medium in place. All of these operations, of modifying pressure, by vacuumizing and/or pressurizing, and thereafter sealing, are effected through the vent hole D in the container and by Way of a single channel or pas sageway leading to the vent hole, as will be hereinafter explained.

After the sealing of the container is completed, the clamping head 23 is lif ed off the container and the container is removed to a suitable place of deposit and a new container placed on the pad 22 for a repeat operation of the machine to seal the new container. Feeding of the container to and from the pad 22 may be effected in any conventional manner.

The string H of rubber from which the plug E is severed, is a substantially continuous string such as may be supplied on a reel, and is fed into the mach ne in stepby-step fashion by a pair of oppositely disposed feed rollers 25', 26 (FIGS. 4, 7 and 8) between which the string H passes. The roller 26 is a positively driven feed roller which is intermittently rotated in a feeding direction by a ratchet device. For this purpose the roller 26 is mounted on a ratchet shaft 27 which is journaled in bearings 23 depending from and formed as a part of a horizontal slide table Ed on a frame 30 which constitutes the main frame of the machine.

At its outer end, the ratchet shaft 27 carries a ratchet wheel 32 which is engaged by a pawl 33 carried on a ratchet collar 34 loosely mounted on the shaft 27. The

'collar 34 is connected by a link 36 to one end of a cam lever 37 which at its opposite end is mounted on a pivot stud 38 secured in the main frame 30 (see also FIG. 3).

Intermediate its ends, the cam lever 37 carries a cam roller 39 (FIG. 4) which operates in a cam groove 41 3 of a face cam 42 which is mounted on and rotates with a main drive shaft 43 (FIG. 3). The drive shaft 43 is journaled in bearings 44 in the main frame 30 and is rotated in any suitable manner.

Thus through rotation of the drive shaft 43, the cam 42 rocks the cam lever 37 and the ratchet collar 34, and hence causes the pawl 33 to rotate the ratchet Wheel 32 and the feed roller 26 in a feeding direction and in a step-by-step manner. 1

The opposite feed roller 25 is a pressure roller and merely presses the string H against the feed roller 26 to effect advancement of the string. This roller 25 is mounted on a stud 46 (FIG. 8) threadedly secured in a bracket 47 pivoted on a pin 43 (FIG. 4) in the machine frame. The bracket 47 is spring loaded as shown in FIG. 8 to urge the pressure roller 25 toward the feed roller 26.

Below the feed rollers 25, 26, as viewed in FIG. 7, the string H of rubber passes through a guide 51 which keeps the string traveling in a straight line vertical direction.

Above the feed rollers 25, 26, the rollers feed the string into and through a guide bushing 52 which is threadedly secured in the slide table 29. The upper end of the bushing 52 is provided with a flat top shear head 53 which engages against the bottom flat face of the slide 21 as shown in FIG. 7, for cooperation With the slide in cutting a plug E from the string H.

The cut-off transfer slide 21 is disposed in a horizontal slideway 55 formed in the slide table 29 and extends through the sealing station I as shown in FIGS. 3, 6 and 7. This slide contains a vertical cut-off hole 56 which extends entirely through the slide and which in the normal or retracted position of the slide as shown in FIG. 7, is in axial alignment with the guide hole in the guide bushing 52 and shear head 53. These holes are substantially the same diameter as the diameter of the string H of rubber so that the string is firmly confined in the holes.

During a feeding operation of the string H the upper or free end of the string is fed into the aligned cut-off hole 56 in the slide 21. Following this feeding operation and While the string H is at rest, the slide 21 is shifted toward the left in FIG. 7 to accomplish two things. The shifting of the slide first cuts off the end of the string H by a shearing action at the point where the bottom face of the slide engages and rides on the top fiat face of the shear head 53, to produce the plug E, and secondly and by the same shifting movement carries or transfers the cut-off plug into a predetermined position at the sealing station J, as shown in FIG. 6, where the slide temporarily remains at rest during the subsequent vacuumizing, pressurizing and sealing operations to be hereinafter explained. Stops 58, 59 (FIGS. 3 and 7) at the ends of the slideway stop the slide 21 in proper position at the string feeding station and at the sealing station.

This shifting of the slide 21 preferably is effected by cam action. For this purpose one end of the slide 21 is yieldably connected to one end of a cam lever 61 (FIGS. 3 and 4) which at its opposite end is mounted on a pivot pin 62 in a bracket 63 attached to the main frame 31). Intermediate its ends, the cam lever 61 carries a cam roller 64 which operates in a cam groove 65 of a barrel cam 66 mounted on and rotating with the drive shaft 53. In this manner the cam 66 and the slide 21 are actuated in tilrlned relation with the other moving parts of the mac me.

At the sealing station I the slide 21 locates and holds the plug E at the lower end of and in axial alignment with a cylindrical channel or passage 71 (FIG. 6) having an inside diameter substantially equal to the outside diameter of the plug and extending vertically and entirely through a cylindrical sealing head 72. This sealing head 72 at its lower end is threadedly engaged in a block 73 mounted on and secured to the top of the slide table 29.

The upper end of the sealing head 72 is enlarged and is provided with a rounded upper face 74 of substantially the same curvature as the container bottom B for sealing engagement thereagainst as shown in FIG. 6. At this upper end of the sealing head 72 the channel 71 tapers inwardly substantially to the sealing face 74, to a reduced diameter substantially equal to the diameter of the vent hole D in the container bottom.

When the container A is on the pad 22 as shown in FIG. 6, the pad locates the container in a centralized position with the vent hole D in vertical alignment with the sealing head channel 71. This is brought about by a locating shoulder 76 on the pad 22 and which fits inside of the container bottom in engagement with the inner face of the double seam C.

When the container A is clamped tight against the pad 22 by the pressure head 23 as hereinbefore mentioned, the pressure head pushes the container down until the bottom B of the container engages against the sealing face 74 of the sealing head 72, as shown in FIG. 6 and this provides a seal around the vent hole D and locates the vent hole indirect communication with the channel 71 in the sealing head 72. For this purpose, the pad 22 is formed with a depending hub 7 8 which surrounds and slides on a tubular bearing 79 extending up from the block 73. A compression spring 81 interposed between the pad 22 and the block 73 provides for yieldability of the pad 22 while a U-shaped washer 82 disposed above the pad in an annular groove 83 in the sealing head 72 holds the pad against displacement from the bearing 79.

The tubular bearing 79 surrounds the intermediate portion of the sealing head 72 in spaced relation thereto so as to provide an annular space or passage 85 therearound. At its upper end, the bearing seats against the lower face of the enlarged portion of the sealing head and thereby seals off this end of the passage. At its lower end the passage is sealed by the block 73. This passage is the vacuumizing and pressurizing passage and is in communication with the channel 71 by way of a plurality of radial ports 87 (FIG. 6) in the sealing head 72 near its enlarged head.

Vacuumization of the container A is effected through a tube 91 (FIGS. 3 and 6) which at one end is threaded into the block 73 and is in communication with the passage 85 around the sealing head 72. The opposite end of the tube 91 is connected to a conventional valve 92 (FIG. 3) which is part of a supply line 93 leading to a suitable source of vacuum. The valve 92, preferably is of the type actuated by an electric solenoid connected by wires 94 (FIG. 3) to an electric switch 95 (see also FIG. 4) operated at the proper time in the cycle of operation of the machine, by a cam shoe 96 on the face cam 42, to open the valve 92. The opening of the valve 92, opens a path of travel from the container A, through its vent hole D (FIG. 6), channel 71 and ports 87 of the sealing head 72, passages 85, tube 91, valve 92 and vacuum line 93 to the source of vacuum to exhaust the air from the desired space in the container.

When the cam shoe 96 rotates out of range of the switch 95, the solenoid actuated valve 92 closes and thereby terminates the vacuumizing action. The container A is then pressurized through the same path of travel excepting that the vacuum valve 92 is cut out. For this purpose the tube 91 is connected by a pipe 98 (FIG. 3) to an electric solenoid actuated pressure valve 99 which is part of a gas supply line 100 which leads from a suitable source of fluid pressure medium such as nitrogen gas or the like under pressure. The solenoid of the pressure valve 99 is connected by wires 101 to an electric switch 102 which at the proper time in the cycle of operation of the machine is actuated by a cam shoe 103 on the cam 42, to open the valve 99. Opening of the pressure valve 99 admits the gas to the pipe 98, tube 91, passage 85 (FIG. 6), ports 87 and channel 71, vent hole D for entrance into the container.

When the cam shoe 103 rotates out of range of the switch 102, the solenoid actuated valve 99 closes and thereby terminates the pressurizing action.

Following the vacuumizing and pressurizing operations, the vent hole D is sealed by the plug E, which is now pushed up through the channel 71 in the sealing head 72. As the plug nears the top open tapered end of the channel 71, it is compressed to substantially the same diameter as the vent hole D and is immediately pushed through the vent hole for approximately one half of the length of the plug. As soon as the plug enters the vent hole it expands to its original diameter beyond the hole and thereby seals itself in place in the hole. The lower end of the plug remains in the tapered portion of the channel 71 until the pressure head 23 releases the container and permits the pad 22 to lift it free of the sealing head 72. The outer end of the plug is thereby withdrawn from the channel 71 and immediately expands over the outer face of the container bottom B to completely seal the vent hole D as shown in FIG. 2. Thus the single channel 71 in the sealing head 72 is utilized to vacuumize, pressurize and seal the vent hole in the bottom of the container.

Pushing of the plug E from its slide 21, up into and through the channel 71 of sealing head 72 and thence into the vent hole D of the container is effected in one operation by an upward stroke of a pusher rod 108 (FIGS. 5, 6 and 7) which is located in a vertical position under the slide 21 in axial alignment with the channel 71 of the sealing head 72. The upper end of the pusher rod 108 is disposed in a vertical guide hole 109 in the slide table 29. At its lower end the rod is secured in a slide 111 (FIG. 5) which operates in a vertical slideway 112 in the main frame 30.

The pusher slide 111 is preferably actuated by cam action. For this purpose, the slide is yieldably connected by a spring loaded link 114 to one end of a cam lever 115 mounted at its opposite end on a pivot pin 116 in the main frame 30. Intermediate its ends, the lever 115 carries a cam roller 117 which operates in a cam groove 118 of a face cam 119 mounted on and rotating with the drive shaft 43. In this manner the actuation of the pusher rod 108 is effected in timed relation with the operation of the other movable parts of the machine.

In a similar manner, the pressure head 23 is actuated by cam action in time with the other moving parts of the machine. For this purpose the pressure head 23 is fixed to a head slide 122 (FIGS. 3 and 5) which operates in the upper end of the slideway 112, above the pusher slide 1111. This head slide 122 is yieldably connected to a spring loaded link 123 which is connected to one end of a cam lever 124- the opposite end of which is mounted on a pivot pin 125 in the main frame 30. Intermediate its ends the lever 124 carries a cam roller 126 which operates in a cam groove 127 of a face cam 128 mounted on and rotating with the drive shaft 43.

Upon completion of the plug insertion or sealing operation, the pusher rod 108 is retracted to the position shown in FIGS. 5 and 6 and following this the cut-offt-ransfer slide 21 is retracted to receive the string H of rubber in preparation for the cutting off of a new plug. Simultaneously with these actions the pressure head 23 moves up and releases the sealed container A so that it may be removed and replaced by a new unsealed container for a repeat cycle of operation of the machine.

It is thought that the invention and many of its attendant advantages :will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore describing being merely a preferred embodiment thereof.

1 claim:

1. A machine for sealing a vent hole in a container with a resilient plug, comprising a support for holding a 6 container in an upright position, a sealing head disposed adjacent said support, said sealing head being formed with an open end channel extending therethrough and having a transverse section substantially the same as that of a said plug throughout substantially the length of the channel, said channel terminating at its discharge end in an inwardly tapering portion and a hole substantially conforming to the size and shape of a said vent hole, saidsupport having locating means for locating a container with its vent hole in alignment with said discharge end of the channel, means for pressing said sealing head into sealing engagement with said container, pressure modifying means communicating with said channel for changing the pressure in said container through said channel and said vent hole, pusher means operable in said channel for pushing a said resilient plug through said channel and into said vent hole by about half the length of said plug, said plug being compressed laterally to the size said vent hole as it passes through said tapered portion of the channel and a portion of the trailing end of the plug being left temporarily in said tapered portion, and means for moving said support and sealing head axially relative to each other to effect withdrawal of said sealing head from said container and from said portion of the plug left temporarily in said channel.

2. A machine for sealing a vent hole in a container with a resilient plug, comprising a support for holding a container in a predetermined upright position, a sealing head disposed adjacent said support, said sealing head being formed with a straight channel extending therethrough and having a transverse section substantially the same as that of a said plug throughout substantially the length of the channel between its inlet and discharge ends, said channel terminating at its discharge end in an upwardly tapering portion and a hole substantially conforming to the size and shape of a said vent hole, said support having locating means for locating a container with its vent hole in alignment with said discharge end of the channel, means for pressing said sealing head into sealing engagement with said container, pressure modifying means communicating with said channel between its inlet and discharge ends for changing the pressure in said container through said channel and said vent hole, means adjacent said inlet end of the channel for feeding a said plug to said inlet end and for retain ing it in position at said inlet end while the pressure in said container is being modified, pusher means operable in said channel for pushing said resilient plug through said channel and into said vent hole by about half the length of said plug, said plug being compressed laterally to the size of said vent hole as it passes through said tapered portion of the channel and a portion of the trailing end of the plug being left temporarily in said tapered portion, and means for moving said support and sealing head axially relative to each other to effect withdrawal of said sealing head from said container and from said portion of the plug left temporarily in said channel.

3. A machine of the character defined in claim 2 wherein said means adjacent said inlet end of the channel comprises a guide bushing formed with a passage thcrethrough for supporting a string of resilient plugging material, said bushing having a shear head at the discharge end of said passage, a movable cut-off transfer member disposed in close sliding contact across said inlet end of the channel and across said shear head, said transfer member having an opening therein for receiving and laterally closely confining a plug of predetermined length at the leading end of said string of plugging material, means for moving said cut-off transfer member across said shear head to shear said plug from said string and for feeding said plug to said inlet end of the channel and for retaining it in stopping position at said inlet end of the channel while the pressure in said container is being modified.

4. A machine of the character defined in claim 3 wherein there is provided means for actuating said pressing means, said pressure modifying means, and said pusher means in timed relation. 1

5. A machine of the character defined in claim 2 wherein said sealing head adjacent the discharge end of said channel is formed with a sealing .face shaped .to the contour of the Wall of said container around said vent hole for sealing engagement against said Wall.

6. A machine of the character defined in claim 2 wherein said pressure modifying means includes means for successively vacuumizing and pressurizing said container through said channel and said vent hole.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A MACHINE FOR SEALING A VENT HOLE IN A CONTAINER WITH A RESILIENT PLUG, COMPRISING A SUPPORT FOR HOLDING A CONTAINER IN AN UPRIGHT POSITION, A SEALING HEAD DISPOSED ADJACENT SAID SUPPORT, SAID SEALING HEAD BEING FORMED WITH AN OPEN END CHANNEL EXTENDING THERETHROUGH AND HAVING A TRANSVERSE SECTION SUBSTANTIALLY THE SAME AS THAT OF A SAID PLUG THROUGHOUT SUBSTANTIALLY THE LENGTH OF THE CHANNEL, SAID CHANNEL TERMINATING AT ITS DISCHARGE END IN AN INWARDLY TAPERING PORTION AND A HOLE SUBSTANTIALLY CONFORMING TO THE SIZE AND SHAPE OF A SAID VENT HOLE, SAID SUPPORT HAVING LOCATING MEANS FOR LOCATING A CONTAINER WITH ITS VENT HOLE IN ALIGNMENT WITH SAID DISCHARGE END OF THE CHANNEL, MEANS FOR PRESSING SAID SEALING HEAD INTO SEALING ENGAGEMENT WITH SAID CONTAINER, PRESSURE MODIFYING MEANS COMMUNICATING WITH SAID CHANNEL FOR CHANGING THE PRESSURE IN SAID CONTAINER THROUGH SAID CHANNEL AND SAID VENT HOLE, PUSHER MEANS OPERABLE IN SAID CHANNEL FOR PUSHING A SAID RESILIENT PLUG THROUGH SAID CHANNEL AND INTO SAID VENT HOLE BY ABOUT HALF THE LENGTH OF SAID PLUG, SAID PLUG BEING COMPRESSED LATERALLY TO THE SIZE SAID VENT HOLE AS IT PASSES THROUGH SAID TAPERED PORTION OF THE CHANNEL AND A PORTION OF THE TRAILING END OF THE PLUG BEING LEFT TEMPORARILY IN SAID TAPERED PORTION, AND MEANS FOR MOVING SAID SUPPORT AND SEALING HEAD AXIALLY RELATIVE TO EACH OTHER TO EFFECT WITHDRAWAL OF SAID SEALING HEAD FROM SAID CONTAINER AND FROM SAID PORTION OF THE PLUG LEFT TEMPORARILY IN SAID CHANNEL. 